Updated the checkout to use branch instead of commit

Author: ritwik-g

.github/workflows/update-docs.yml

@@ -21,6 +21,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v4
+      with:
+        ref: ${{ github.event.pull_request.head.ref }}
+        repository: ${{ github.event.pull_request.head.repo.full_name }}
+        fetch-depth: 0
 
     - name: Set up Python
       uses: actions/setup-python@v4